Updated allocation pool checks

As per the REST Networking API v2.0 (Subnet) docs, if subnets pools
are not specified, OpenStack networking automatically allocates pools
covering all IP addresses in the CIDR.

In custom vendor specific environments, subnets can be created without
allocation pools via UI due to which subnets will not have any existing
allocation pools. Under this scenario, module throws an
"IndexError: list index out of range" error.

Also, allow to add more allocation pools on top of existing allocation
pools.

Change-Id: Ib8becf5e958f1bc8e5c9fd76f1722536bf1c9f1a

ci/roles/subnet/tasks/main.yml

@@ -41,3 +41,6 @@
     cloud: "{{ cloud }}"
     name: "{{ network_name }}"
     state: absent
+
+- name: Subnet Allocation
+  include_tasks: subnet-allocation.yml

ci/roles/subnet/tasks/subnet-allocation.yml

@@ -0,0 +1,63 @@
+---
+- name: Create network {{ network_name }}
+  openstack.cloud.os_network:
+    cloud: "{{ cloud }}"
+    name: "{{ network_name }}"
+    state: present
+
+- name: Create subnet {{ subnet_name }} on network {{ network_name }}
+  openstack.cloud.os_subnet:
+    cloud: "{{ cloud }}"
+    network_name: "{{ network_name }}"
+    enable_dhcp: "{{ enable_subnet_dhcp }}"
+    name: "{{ subnet_name }}"
+    state: present
+    cidr: 192.168.0.0/24
+    gateway_ip: 192.168.0.1
+    allocation_pool_start: 192.168.0.2
+    allocation_pool_end: 192.168.0.4
+
+- name: Update subnet {{ subnet_name }} allocation pools
+  openstack.cloud.os_subnet:
+    cloud: "{{ cloud }}"
+    network_name: "{{ network_name }}"
+    name: "{{ subnet_name }}"
+    state: present
+    cidr: 192.168.0.0/24
+    allocation_pool_start: 192.168.0.5
+    allocation_pool_end: 192.168.0.8
+
+- name: Get Subnet Info
+  openstack.cloud.os_subnets_info:
+    cloud: "{{ cloud }}"
+    name: "{{ subnet_name }}"
+  register: subnet_result
+
+- name: Verify Subnet Allocation Pools Exist
+  assert:
+    that:
+      - subnet_result.openstack_subnets is defined
+      - subnet_result.openstack_subnets | length == 1
+      - subnet_result.openstack_subnets[0].allocation_pools is defined
+      - subnet_result.openstack_subnets[0].allocation_pools | length == 2
+
+- name: Verify Subnet Allocation Pools
+  assert:
+    that:
+      - subnet_result.openstack_subnets[0].allocation_pools | selectattr('start','equalto',item.start) | list | count > 0
+      - subnet_result.openstack_subnets[0].allocation_pools | selectattr('end','equalto',item.end) | list | count > 0
+  loop:
+    - {start: '192.168.0.2', end: '192.168.0.4'}
+    - {start: '192.168.0.5', end: '192.168.0.8'}
+
+- name: Delete subnet {{ subnet_name }}
+  openstack.cloud.os_subnet:
+    cloud: "{{ cloud }}"
+    name: "{{ subnet_name }}"
+    state: absent
+
+- name: Delete network {{ network_name }}
+  openstack.cloud.os_network:
+    cloud: "{{ cloud }}"
+    name: "{{ network_name }}"
+    state: absent